There is substantial commercial interest in the use of multilayer, weatherable polymeric materials in various product forms such as sheets, films, shaped products, thermoformed articles, packaging, and architectural products, as well as coatings. Many different plastics are used as the base layer, or substrate, in these products in order to take advantage of particular physical, chemical, and mechanical properties. The upper layer, often referred to as the topcoat, often functions to protect the base layer or layers, for example to maintain gloss and shine. However, curing and aging of the layers can result in a color shift, often described as yellowing. This color shift may be observed immediately upon manufacture, or gradually over time. When a white or light colored finish is desired, yellowing of the upper layer is aesthetically undesirable to consumers. Accordingly, there remains a need in the art for weatherable compositions, particularly upper coats, that provide protection to an underlying substrate, and that do not appreciably yellow during use.